This invention relates to a cable-type core barrel.
Basically, the core barrel comprises an inner tube sliding in a set of outer tubes.
The set of outer tubes is provided lowerly with a drill bit, and comprises an annular suspension ledge for the inner tube, and an annular locking groove for the inner tube, located above the suspension ledge.
The inner tube carries an extractor cone at its bottom, and comprises at its top a hooking head provided with an upper cone frustum hook and a release cone. When in its lower core boring position, the inner tube rests against the aforesaid suspension ledge, and can then be locked relative to the set of outer tubes by means of a latch comprising tongues engaged in the said locking groove. The latch is supported by a tubular latch support which is rigid with the inner tube and which does not affect the release of said inner tube. The hooking head for the inner tube is rigid with a release slide which carries a release pin and which slides in the latch support and relative thereto. Furthermore, the inner tube can be released from its core boring position by the release slide, the release pin of which disengages the latch tongues from the locking groove, by means of traction exerted on the cone frustum hook of the inner tube hooking head.